In general, an actuator device that uses a motor as a driving source is provided with a decelerator which decelerates rotation of the motor. For example, a worm & wheel is used in a deceleration mechanism of an actuator device according to Japanese Patent No. 4760204. A wheel gear (worm wheel) as a reduction gear thereof is accommodated in an accommodating member with an axial-direction end surface being in sliding contact with a facing surface.
In addition, the reduction gear and the accommodating member are formed of a resin in the actuator device. Since a resin is used as the material, a high degree of freedom can be ensured for molding. Also, a required strength can be ensured and weight reduction can be achieved.
However, according to the configuration of the related art described above, the sliding contact between the reduction gear and the accommodating member may generate static electricity. Also, the static electricity with which the reduction gear is charged may be discharged to electronic components in the accommodating member beyond an air gap. In this respect, there still remains room for improvement.